Dynamic voxel size tuning for direct laser writing

We present a straightforward method to dynamically tune the voxel size in the multiphoton polymerization technique by changing the incident laser beam diameter with a motorized beam expander. In such a manner, the beam underfilling of the objective aperture leads to an effective numerical aperture drop. Therefore, the voxel could be expanded in the lateral and the axial directions without changing the objective. Here, we present the theoretical simulation analysis of the light intensity distribution for different underfilling conditions, as well as the measured experimental results of the voxel feature sizes for high numerical aperture objective. The presented approach extends technology capabilities and could significantly increase the fabrication speed while maintaining the possibility for obtaining the highest resolution features.